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Science

Diet and digestion

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Chemical digestion

The substances which our body needs cannot be absorbed into the blood until they have been broken down into small, soluble chemicals. This process is called chemical digestion, and it works with the help of enzymes. Once the food is completely digested, its molecules are small enough to pass through the wall of the small intestine by diffusion.

Digestive enzymes

Different enzymes digest different food molecules.

Nutrients and the enzymes that digest them

nutrientdigestive enzymes
carbohydratescarbohydrases
fatslipases
proteinsproteases

Chemical digestion occurs in the mouth, stomach and small intestine. In the stomach, stomach acid helps the enzymes to work.

Bile - higher

Bile is an alkaline substance produced by the liver and stored in the gall bladder. It is secreted into the small intestine, where it emulsifies fats. This is important, because it provides a larger surface area in which the lipases can work.

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